oracle访问Sql server表问题。。。

[phantombig]

--查询不出数据
DECLARE
v_batchno varchar2(50);
BEGIN
v_batchno := '509702C4';
FOR sd IN (SELECT *
FROM (SELECT "F_BatchNo" AS f_batchno FROM tns_m0001) ss
WHERE ss.f_batchno = v_batchno) LOOP
dbms_output.put_line(sd.f_batchno);
END LOOP;
END;

--可以查出数据，打印结果
DECLARE
v_batchno varchar2(50);
BEGIN
v_batchno := '509702C4';
FOR sd IN (SELECT *
FROM (SELECT "F_BatchNo" AS f_batchno FROM tns_m0001) ss
WHERE ss.f_batchno = '509702C4') LOOP
dbms_output.put_line(sd.f_batchno);
END LOOP;
END;

[phantombig]

tns_m0001是SQL server中的表，通过透明网关在ORACLE中建立的同义词。 用ss.f_batchno = v_batchno（变量值为'509702C4'）条件查询不出结果， 用ss.f_batchno = '509702C4'条件则可查询出结果。怎么回事？

[wuyisky84]

没有看明白

[KnowKjava]

batchno